Between Plural Stationary Heads Patents (Class 360/63)
  • Patent number: 9728214
    Abstract: A disk drive according to an embodiment includes a disk, a first actuator having a first arm, a second actuator having a second arm, and a head. The head includes a write head and a read head. In addition, the disk drive includes a control unit calculating an amount of shift from an initial value of offset in a radial direction of the disk between the read head and the write head. The control unit controls the second actuator and corrects a position of the head to a position where the shift amount is reduced.
    Type: Grant
    Filed: March 3, 2016
    Date of Patent: August 8, 2017
    Assignee: Kabushiki Kaisha Toshiba
    Inventor: Masakazu Abe
  • Patent number: 9395531
    Abstract: A spatial light modulator (SLM) module and methods of designing, manufacturing and using the same are provided. In one embodiment, the SLM module comprises a diffractive, diffractive SLM formed on a substrate, the SLM including a plurality of pixels each including a plurality of electrostatically deflectable actuators, and a driver including a number of drive channels each coupled to one of the plurality of electrostatically deflectable actuators. Each of the drive channels include at least one internal digital-to-analog converter (DAC) integrally formed on the same substrate as the SLM. In one embodiment, the DAC is a multi-slope charge integrating DAC. In other embodiments, the driver includes circuitry to test each of the drive channels, and a spare drive channel that can be switched in to replace a defective drive channel.
    Type: Grant
    Filed: March 6, 2013
    Date of Patent: July 19, 2016
    Assignee: Silicon Light Machines Corporation
    Inventor: Michael Yeung
  • Patent number: 9177582
    Abstract: In a disk apparatus, media include first and second surfaces having first and second servo patterns which are read at different timings by first and second heads. A controller controls the first head based on a first demodulated position obtained by demodulating the first servo pattern and a target position. The controller calculates a first estimated demodulated position from the demodulated position and a first demodulated velocity based on the first servo patterns, calculates a second estimated demodulated position from the first demodulated position and a second demodulated velocity based on the second servo patterns, and stops writing operation of the first head in accordance with one of the first and second estimated demodulated positions exceeding a threshold.
    Type: Grant
    Filed: April 23, 2015
    Date of Patent: November 3, 2015
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Takayuki Kawabe, Masahide Kanegae
  • Patent number: 9087508
    Abstract: Systems and methods are provided for causing aural and/or visual presentation of representative content in response to a request to progress or navigate through audio content at a scan rate exceeding a threshold playback rate. In some embodiments, a current position marker in the audio content may be repeatedly updated based on the scan rate. For each updated position of the current position marker, one or more characteristic words associated with the content near the current position marker may be determined. A continuous presentation of the determined characteristic words may be generated and presented aurally and/or visually in order to provide an indication as to the subject matter of the content at the current position.
    Type: Grant
    Filed: October 18, 2012
    Date of Patent: July 21, 2015
    Assignee: Audible, Inc.
    Inventor: Steven Charles Dzik
  • Patent number: 9070406
    Abstract: A disk drive is disclosed comprising a disk comprising a plurality of tracks, and a head comprising a first read element and a second read element. A spacing of the first and second read elements is measured, and based on the measured spacing, the tracks are grouped into radial bands that define at least one one-dimensional recording area on the disk and at least one two-dimensional recording area on the disk. When the head is within a first two-dimensional recording area, data recorded on the disk is detected by processing a first read signal generated by the first read element and by processing a second read signal generated by the second read element using a two-dimensional demodulation algorithm. When the head is within a first one-dimensional recording area, data recorded on the disk is detected by processing the first read signal using a one-dimensional demodulation algorithm.
    Type: Grant
    Filed: June 13, 2014
    Date of Patent: June 30, 2015
    Assignee: Western Digital Technologies, Inc.
    Inventors: Shaoping Li, Gerardo A. Bertero, Donald Brunnett
  • Patent number: 9032167
    Abstract: Computer readable media, methods and apparatuses are disclosed that may be configured for sequentially reading data of a file stored on a storage medium. The disclosure also provides for alternating writing, in a sequential order, portions of the file data to a first buffer and a second buffer. The disclosure also provides for writing from a first buffer and a second buffer to a first track until the first track is filled.
    Type: Grant
    Filed: December 23, 2013
    Date of Patent: May 12, 2015
    Assignee: Comcast Cable Communications, LLC
    Inventor: Niraj K. Sharma
  • Publication number: 20150092295
    Abstract: A method for operating a tape storage system includes simultaneously receiving readback signals from a set of data readers reading from data tracks of a set of adjacent data tracks extending along a longitudinal extension of a tape storage medium. Each data track has a width and each data reader has a width that exceeds the width of a data track. In the readback signal, of one of the data readers of the set a simultaneous presence of two defined waveforms is detected stemming from two different servo patterns arranged in servo sections of adjacent data tracks of the set. At least one of lateral position, velocity, gain and timing information is derived from a measure of the energy of the two defined waveforms detected in the readback signal of the data reader and applying this information in the operation of the tape storage system.
    Type: Application
    Filed: September 17, 2014
    Publication date: April 2, 2015
    Inventors: Giovanni Cherubini, Simeon Furrer, Jens Jelitto, Mark A. Lantz
  • Publication number: 20150092294
    Abstract: In a method for operating a tape storage system, readback signals are simultaneously received from a set of data readers reading from data tracks of a set of adjacent data tracks extending along a longitudinal extension of a tape storage medium, wherein each data track of the set has a width and each data reader of the set has a width equal to or less than the width of a data track. Simultaneously to receiving the readback signals from the set of data readers readback signals are received from a servo reader arrangement containing at least one servo reader arranged laterally offset from one of the data readers by less than the width of a data track. At least one of lateral position, velocity, gain and timing information is determined dependent on the readback signals of each servo reader in the servo reader arrangement.
    Type: Application
    Filed: September 17, 2014
    Publication date: April 2, 2015
    Inventors: Giovanni Cherubini, Simeon Furrer, Jens Jelitto, Mark A. Lantz
  • Patent number: 8982495
    Abstract: An apparatus according to one embodiment includes a plurality of modules configured to at least read data stored on a magnetic recording tape, each of the modules having an array of readers. One module is configured to read data on a magnetic recording tape which none of the other modules can read. An apparatus according to another embodiment includes a first module configured to at least read data stored on a magnetic recording tape in a first range of formats, and at least a second module configured to at least read data stored on a magnetic recording tape in at least a second range of formats. The first range of formats does not include a format that is in the second range of formats. All of the modules are aligned along a tape travel direction.
    Type: Grant
    Filed: July 9, 2013
    Date of Patent: March 17, 2015
    Assignee: International Business Machines Corporation
    Inventors: Robert G. Biskeborn, Gary M. Decad, Jason Liang
  • Publication number: 20140320997
    Abstract: A system according to one embodiment includes at least two write transducers for writing to a magnetic medium; and a low reluctance path from a first pole of a first of the write transducers to a second pole of a second of the write transducers.
    Type: Application
    Filed: April 24, 2013
    Publication date: October 30, 2014
    Applicant: International Business Machines Corporation
    Inventors: Robert G. Biskeborn, Philipp Herget
  • Patent number: 8693126
    Abstract: An apparatus comprising a magnetic media and a read/write unit. The magnetic media may be configured to store data. The magnetic media may also be rotated during access of the magnetic media. The read/write unit may comprise a plurality of transducers arranged in a linear array. Each of the transducers may be fabricated on a semiconductor substrate with fixed head positions with respect to the magnetic media. The read/write unit may also be positioned in close proximity to and across the surface of the magnetic media. Each transducer may be configured to read data from the magnetic media and write data to the magnetic media.
    Type: Grant
    Filed: July 21, 2010
    Date of Patent: April 8, 2014
    Assignee: LSI Corporation
    Inventors: Wayne L. Buckholdt, Robert W. Warren
  • Patent number: 8639894
    Abstract: Computer readable media, methods and apparatuses are disclosed that may be configured for sequentially reading data of a file stored on a storage medium. The disclosure also provides for alternating transferring of fixed size portions of the file data to a first buffer and a second buffer, alternating processing of data blocks of the fixed sized portions in parallel from the first and second buffers by a plurality of processing threads, and outputting the processed data blocks.
    Type: Grant
    Filed: January 27, 2012
    Date of Patent: January 28, 2014
    Assignee: Comcast Cable Communications, LLC
    Inventor: Niraj K. Sharma
  • Patent number: 8339728
    Abstract: Example embodiments may provide a magnetic memory device. The example embodiment magnetic memory devices may include a plurality of memory tracks, bit lines, connectors, a first input portion, and/or selectors. The memory track(s) may be stacked on a substrate to form a multi-stack. A plurality of magnetic domains may be formed in the memory track so that a data bit may be represented by a magnetic domain and may be stored in an array. The bit line(s) may be formed along respective memory tracks. The connector(s) may form a magnetic tunnel junction (MTJ) cell with one data bit region of the memory track. The first input portion may be electrically connected to each memory track and may input a magnetic domain motion signal to move data stored on a data bit region of the memory track to an adjoining data bit region. The selector(s) may select a memory track from a plurality of memory tracks on which a reading and/or writing operation may to be performed.
    Type: Grant
    Filed: February 21, 2007
    Date of Patent: December 25, 2012
    Assignee: Samsung Electronics Co., Ltd.
    Inventors: Kee-won Kim, Tae-wan Kim, Young-jin Cho, In-jun Hwang
  • Patent number: 8310777
    Abstract: In one general embodiment, a recording system controller includes a controller controlling a timing of flux switching of adjacent pairs of writers such that the writers in a given pair do not switch substantially concurrently, and reducing a current of one of the writers in the pair while the adjacent writer is writing a transition. In another general embodiment, a recording system controller includes a controller controlling a timing of pulse writing of adjacent pairs of writers such that the writers in a given pair do not pulse substantially concurrently. In yet another general embodiment, a method includes controlling a timing of pulse writing or flux switching of adjacent pairs of writers such that the writers in a given pair do not pulse or switch substantially concurrently.
    Type: Grant
    Filed: September 9, 2009
    Date of Patent: November 13, 2012
    Assignee: International Business Machines Corporation
    Inventors: Robert G. Biskeborn, Philipp Herget, Pierre-Olivier Jubert
  • Patent number: 8159770
    Abstract: A sequential information storage medium, comprising a plurality of servo patterns encoded lengthwise thereon, wherein each servo pattern encodes at least one LPOS bit and comprises a width less than 187 microns.
    Type: Grant
    Filed: January 13, 2009
    Date of Patent: April 17, 2012
    Assignee: International Business Machines Corporation
    Inventors: Nhan Xuan Bui, Reed Alan Hancock, Robert Allen Hutchins, Larry Leeroy Tretter
  • Patent number: 8154819
    Abstract: The flying heights of magnetic heads of a disk drive are set using an FOD (flying on demand) method in a bank mode. A first signal for adjusting the flying height of a magnetic head is issued to each magnetic head and the value of the first signal is scaled by scale values set for the magnetic heads, respectively, with one of the scale values differing from the others. The value of the first signal is changed until the magnetic head associated with the scale value different from the others touches down. A flying height for the magnetic head which touched down is determined based on the value of the first signal at the time of touch-down. The process is repeated, however with a different bank of scale values each time and set in such a way as to cause the sequential touch-down of the remaining magnetic heads, and determinations of flying heights for the magnetic heads.
    Type: Grant
    Filed: May 6, 2010
    Date of Patent: April 10, 2012
    Assignee: Seagate Technology International
    Inventors: Ho-chul Shin, Da-woon Chung
  • Patent number: 8130461
    Abstract: A recording system controller according to one embodiment includes a controller capable of selecting a level of a current or voltage applied to a first writer during the creation of a magnetic transition based on a current in at least one nearby writer. A recording system controller according to another embodiment includes a controller capable of selecting a timing of a current change applied to a first writer based on a current in at least one nearby writer for compensating for an effect of crosstalk from the at least one nearby writer. A method according to yet another embodiment includes selecting a level of a current or voltage applied to a first writer or selecting a timing of a current change applied to the first writer based on a current in at least one nearby writer for compensating for an effect of crosstalk from the at least one nearby writer.
    Type: Grant
    Filed: November 10, 2009
    Date of Patent: March 6, 2012
    Assignee: International Business Machines Corporation
    Inventors: Robert G. Biskeborn, Philipp Herget, Wayne I. Imaino
  • Patent number: 8009376
    Abstract: Embodiments of the present invention help to improve the capacity and the performance of a disk drive device. According to one embodiment, a data track pitch is set to each recording surface. The recording surfaces are divided into bands. A hard disk drive (HDD) sequentially moves a head to an adjacent data track in a band and performs a head switch at the band end in its data accessing. On a recording surface, the number of data tracks in each band is variable; and each band is constituted by different number of data tracks as necessary. The number of data tracks in each band is set so that the radial position of the band end comes close to the radial position of the corresponding band end on another recording surface. Accordingly, even if the recording surfaces have different variation rates of the data track pitch in the radial direction, increase in process time due to head switches can be suppressed.
    Type: Grant
    Filed: September 12, 2008
    Date of Patent: August 30, 2011
    Assignee: Hitachi Global Storage Technologies, Netherlands, B.V.
    Inventors: Takahiro Saito, Kazunari Tsuchimoto, Atsushi Kanamaru
  • Patent number: 7724459
    Abstract: A method for reading data from a magnetic recording tape having multiple adjacent data tracks according to one embodiment includes simultaneously detecting signals from a plurality of read devices, at least some of the read devices being positioned over multiple data tracks while other of the adjacent read devices are positioned over single data tracks; determining which of the read devices is positioned over a single data track; and simultaneously reading data from the data tracks using only those read devices over the single data tracks. A method for reading and writing data to a magnetic recording tape according to another embodiment includes simultaneously writing data tracks to a magnetic medium; and simultaneously reading the data tracks on the magnetic medium using a plurality of adjacent read devices; wherein the number of the adjacent read devices is at least twice the number of the adjacent write devices.
    Type: Grant
    Filed: September 5, 2008
    Date of Patent: May 25, 2010
    Assignee: International Business Machines Corporation
    Inventors: W. Stanley Czarnecki, Icko E. Iben
  • Patent number: 7679854
    Abstract: A disk drive for implementing a head switch operation is disclosed. The disk drive comprises: an actuator; a first head and a second head attached to the actuator; a disk having a plurality of tracks; and a processor. The processor controls operations in the disk drive including: executing a head switch command from the first head to the second head; determining that a sync-up operation is not successful for the second head at a first track; applying a torque to the actuator to move the second head to a second track; and determining that the sync-up operation is successful.
    Type: Grant
    Filed: October 29, 2008
    Date of Patent: March 16, 2010
    Assignee: Western Digital Technologies, Inc.
    Inventors: Aswartha Narayana, John Yin Kwong Li, Gary Gaoxiang Zhu, Jonathan V. Nguyen, Duc T. Phan
  • Patent number: 7646558
    Abstract: In one embodiment of a system and method for positioning a transducer head, the transducer head includes a first group of elements for reading data from or writing data to a set of tracks on a storage medium, and a second group of elements for reading data from or writing data to a set of tracks on a storage medium. A device supplies electrical power to the first group of elements to read data from or write data to a first position on the storage medium, and supplies electrical power to the second group of elements to read data from or write data to a second position on the storage medium different than the first position without coarse movement of the transducer head relative to the storage medium.
    Type: Grant
    Filed: January 23, 2007
    Date of Patent: January 12, 2010
    Assignee: Sun Microsystems, Inc.
    Inventors: Darryl W. Yeakley, William J. Vanderheyden
  • Publication number: 20090170578
    Abstract: A method of providing audio transmissions from an electronic device having internal audio multiplexing is disclosed. The method comprises combining a plurality of received audio input signals for output as a first mode of operation for the electronic device, where the electronic device is configured to output the plurality of audio input signals on at least one audio channel. When a priority audio signal is detected from one of the received audio input signals in the first mode of operation, the method interrupts playback of the remaining audio input signals with the priority audio signal as a second mode of operation for the electronic device and transfers, within the electronic device, the priority audio signal to the at least one audio channel once the priority audio signal is detected.
    Type: Application
    Filed: January 2, 2008
    Publication date: July 2, 2009
    Applicant: HONEYWELL INTERNATIONAL INC.
    Inventors: Manuel F. Richey, Phillip G. Holloway, Zachary R. Nelson, Jeffrey K. Hunter, Michael P. Ramsey
  • Patent number: 7492545
    Abstract: A system and method for a servo controller (SC) used in an embedded disk controller for adjusting stored servo skew values based on measured skew values is provided. The system includes, a servo timing controller, wherein the servo timing controller includes a first register that stores measured servo skew values at a given time; a first set of registers that receive stored skew values and the measured skew values; and firmware that adjusts the skew values based on the measured skew values measured by a reference timer. The process includes, measuring actual skew values during a head change in a read operation; comparing the measured skew values with the stored skew values; adjusting the skew value based on the comparison; and adjusting a servo field timer based on the adjusted skew value.
    Type: Grant
    Filed: March 10, 2003
    Date of Patent: February 17, 2009
    Assignee: Marvell International Ltd.
    Inventors: Michael R. Spaur, Raymond A. Sandoval
  • Patent number: 7474488
    Abstract: A system such as a tape head having multiple read devices, where the read devices have less than or equal to half the width of the write devices or data tracks. The read devices are aligned adjacent to one another in the track width direction. Data tracks and guide bands can be used for track following, while a preferred embodiment uses additional readers to read servo bands for track following purposes.
    Type: Grant
    Filed: August 30, 2005
    Date of Patent: January 6, 2009
    Assignee: International Business Machines Corporation
    Inventors: W. Stanley Czarnecki, Icko E. T Iben
  • Patent number: 7466506
    Abstract: A magnetic recording disk drive has disks with identical pre-patterned servo patterns on their front and back surfaces and a servo control system for positioning the read/write heads using the servo signals from the identical servo patterns. The servo sectors on the two disk surfaces form identical patterns of angularly spaced arcuate-shaped lines that extend generally radially across the data tracks. The arcuate-shaped lines on one surface, the front surface, generally replicate the path of the recording head as it is moved across the data tracks by a rotary actuator, so that there is a constant sampling rate of the servo sectors on the front surface regardless of radial position of the head. However, the arcuate-shaped lines on the other surface, the back surface, do not replicate the path of the recording head so the servo sampling rate is not constant but varies with radial position of the head.
    Type: Grant
    Filed: June 19, 2007
    Date of Patent: December 16, 2008
    Assignee: Hitachi Global Storage Technologies Netherlands B.V.
    Inventors: Thomas R. Albrecht, Zvonimir Z. Bandic
  • Patent number: 7436614
    Abstract: Embodiments of the invention provide a data storage device and its control method that are capable of minimizing the possibility of head deterioration while maintaining the minimum required sustained data rate. In one embodiment, each track is divided into three areas (A, B, and C). When a ? track is accessed, the head is changed to access a ? track on the next recording surface. In this instance, LBAs are assigned to disks so that heads Hd0 through Hd4, which access both surfaces of disks 0 and 1, are selected for accessing purposes in the Hd0, Hd1, Hd2, Hd3, Hd0, and Hd1 order while an area selection is made in the area A, area B, and area C order.
    Type: Grant
    Filed: June 1, 2005
    Date of Patent: October 14, 2008
    Assignee: Hitachi Global Storage Technologies Netherlands B.V.
    Inventor: Hiroshi Uchida
  • Patent number: 7379257
    Abstract: A magnetic disk drive includes an actuator arm, a suspension fixed to a tip end of the actuator arm, and a head slider having at least two electromagnetic transducers mounted at a tip end of the suspension. The head slider has a first electromagnetic transducer inclined in a direction in which the inner side face side is nearer to an air outflow end than a central portion thereof, and a second electromagnetic transducer inclined in a direction in which the outer side face side is nearer to the air outflow side than the central portion thereof. A controller performs changeover control such that an inner side data region of a magnetic disk is taken charge of by the first electromagnetic transducer while an outer side data region is taken charge of by the second electromagnetic transducer.
    Type: Grant
    Filed: September 14, 2005
    Date of Patent: May 27, 2008
    Assignee: Fujitsu Limited
    Inventor: Michinaga Yamagishi
  • Patent number: 7359134
    Abstract: A disk storage device has a plurality of disk faces and a plurality of heads. The disk storage device protects the data on the disk face for a head before the defect of the head occurs. For each head, a table for accumulating the error generation count generated by the operation of a head is provided. And a control unit predicts the defect of one head based on the accumulated error generation count, reads data on the corresponding disk face by the head of which the defect was predicted, and writes the read data to another corresponding disk face by another head. Since the defect of a head can be predicted, the data can be protected in advance.
    Type: Grant
    Filed: December 12, 2005
    Date of Patent: April 15, 2008
    Assignee: Fujitsu Limited
    Inventor: Masato Komatsu
  • Patent number: 7280298
    Abstract: A set of coils wind around a magnetic core in a thin film magnetic head. Current supplying circuits are separately connected to the individual coils. The individual coils get shorter in the overall length as compared with the case where a set of coils consist of a single conductor. The impedance of the coils can be reduced. The reduction in the impedance enables the flow of the electric current to be established in a moment within the coils. The magnetic field of a sufficient intensity can be generated in a moment. Magnetization of a sufficient intensity can thus be established on a magnetic recording medium even when the frequency of a signal for recordation gets higher.
    Type: Grant
    Filed: August 7, 2003
    Date of Patent: October 9, 2007
    Assignee: Fujitsu Limited
    Inventors: Michinaga Yamagishi, Takenori Ohshima
  • Patent number: 7271970
    Abstract: A conventional magnetic head has a structure, in which a MR element and a recording element are stacked. The influence of a recording magnetic field on the magnetically sensitive portion of a reproduction element is lessened and the performance of the MR element is stabilized. Also, the reliability of the magnetic disk drive using a MR element is enhanced. The magnetic disk drive uses a composite magnet head, which has a plurality of reproduction elements arranged such that the magnetically sensitive layer of a reproduction element of the composite magnetic head does not overlap with the normal direction projection of the recording element, and which lessens the influence of a recording magnetic field on the magnetically sensitive portion of each reproduction element.
    Type: Grant
    Filed: October 15, 2004
    Date of Patent: September 18, 2007
    Assignee: Hitachi Global Storage Technologies Japan, Ltd.
    Inventor: Reijiro Tsuchiya
  • Patent number: 7245448
    Abstract: A plurality of recording media combined integrally having a plurality of recording surfaces; and a plurality sets of reading heads and writing heads, combined integrally, provided for the respective ones of the plurality of recording surfaces, are provided. Upon writing data on each recording medium with the writing head provided therefor, a writing position is controlled as a result of positioning information previously provided on the recording media including the recording medium other than the each recording medium being read with the reading heads provided therefor.
    Type: Grant
    Filed: March 15, 2005
    Date of Patent: July 17, 2007
    Assignee: Fujitsu Limited
    Inventor: Yukio Urata
  • Patent number: 7212368
    Abstract: A method and system of switching heads in a hard disk drive written using an off-line STW method. In the method, first, deviations between a reference head and each of the heads are calculated. Next, a mapping table having the deviations between the reference head and each of the heads is generated and stored in a memory. Thereafter, when a head switching operation is requested, a current head is switched to a new head to access a track whose number is the same as the track assessed by the current head. A deviation of a track on which the head is positioned, recorded in the mapping table, is applied to the virtual track address of the track on which the head is positioned, thereby obtaining the physical track address of the track on which the head is positioned. The requested track is then accessed based on the obtained physical track address.
    Type: Grant
    Filed: November 21, 2003
    Date of Patent: May 1, 2007
    Assignee: Samsung Electronics Co., Ltd.
    Inventor: Jae-hyeong Kim
  • Patent number: 7190537
    Abstract: A self-Redundant Array of Inexpensive Disks (RAID) system using a hard disk drive having a backup head and a method of writing data to and reading data from the hard disk drive having the backup head are provided. A self-RAID (Redundant Array of Inexpensive Disks) system using a hard disk drive with at least one writable and readable disk medium includes a spindle motor, heads, an actuator arm, and a controller. The spindle motor rotates the disk medium. The heads face each other above and below the disk medium. The actuator arm drives the heads. The controller controls the heads to write data to and read data from the disk medium using a mode selection signal.
    Type: Grant
    Filed: December 23, 2003
    Date of Patent: March 13, 2007
    Assignee: Samsung Electronics Co., Ltd.
    Inventor: Jin-wan Jun
  • Patent number: 7154688
    Abstract: In a disk device in which heads are positioned by a servo mechanism, the object of the present invention is to prevent data from being destroyed by incorrect selection of a head and to improve reliability in recording or reproducing information and to prevent format efficiency from being decreased thereby. For this object, a SAM pattern in a servo information region is changed for each head and recorded. Then, the SAM pattern is read to determine which head makes access to a disk surface and the head is compared with a head to which a direction of making access is given thereby to make an error check. Moreover, by the use of a marker pattern of rotational synchronization compensating data added to the servo information, an error check of the head making access to the disc surface is conducted.
    Type: Grant
    Filed: February 13, 2003
    Date of Patent: December 26, 2006
    Assignee: Hitachi Global Storage Technologies Japan, Ltd.
    Inventors: Iwao Oshimi, Kiyotada Itou, Katsumoto Onoyama, Yosuke Hamada
  • Patent number: 7119974
    Abstract: A recording system of a magnetic tape drive is operated to cause one separate set of write heads to write data discontinuously to magnetic tape as received, and to save the data, and, during the same operation, to cause another separate set of write heads to rewrite data to magnetic tape in a continuous arrangement. The writing may be in parallel and simultaneous. Thus, during the same operation, and at the same time, the separate sets of the plurality of write heads, temporarily write the received data to magnetic tape so that the sender can erase its copy, and rewrite the saved data to the magnetic tape in a permanent arrangement, without waiting to complete first writing received data, to complete subsequently rewriting the data, and repeating.
    Type: Grant
    Filed: August 11, 2005
    Date of Patent: October 10, 2006
    Assignee: International Business Machines Corporation
    Inventor: Glen Alan Jaquette
  • Patent number: 7075747
    Abstract: A disk device that has displacement of servo signals in the circumference direction and radius direction between a plurality of disks, prevents a drop in performance due to the displacement when the heads are switched. To deal with the displacement in the circumference direction, the sector numbers on the disk are converted by a table for each head. Also the servo gate time is corrected by the table according to the eccentricity of the disk, so the servo signal detection accuracy improves. Also to deal with the displacement in the radius direction, the track numbers on the disk are converted by the table using the difference value based on the reference head.
    Type: Grant
    Filed: May 30, 2003
    Date of Patent: July 11, 2006
    Assignee: Fujitsu Limited
    Inventor: Kazuhiko Takaishi
  • Patent number: 7064913
    Abstract: A recording target error rate is selected for one or more of data storage devices, and for each data storage device, a dither value is determined for each read/write head in the data storage device, wherein for each head, using a dither value for writing data, essentially provides the selected recording target error for all the heads.
    Type: Grant
    Filed: January 9, 2002
    Date of Patent: June 20, 2006
    Assignee: Quantum Corporation
    Inventors: Dan Gunderson, Doug Gunther
  • Patent number: 7023635
    Abstract: A recording/reproducing apparatus capable of switching over among a plurality of heads with high precision, wherein the apparatus is provided with: a recording/reproducing unit for recording/reproducing signals onto/from a recording medium with a plurality of heads; a generating unit for generating control data for controlling the recording/reproducing unit; and a transmitting unit for transmitting control data generated by the generating unit to the recording/reproducing unit, wherein priority is given in transmission to data for controlling the switching of the plurality of heads over other data.
    Type: Grant
    Filed: March 15, 2004
    Date of Patent: April 4, 2006
    Assignee: Hitachi, Ltd.
    Inventors: Shigeru Yamazaki, Kemmei Masuda, Toshio Tsuchiya
  • Patent number: 6980386
    Abstract: A disc drive has transducers supported by an actuator to fly proximate data tracks on surfaces of rotating information storage discs. Each of the discs is partitioned into concentric regions. A control system arranges the deposition of data in write operations to the tracks on the disc surfaces, as data is written to the discs, such that the data is sequentially organized both on the tracks and within each of the regions. The control system writes data from a track adjacent a first region boundary in a first direction to a second region boundary until all tracks in a region are full. The control system executes a head switch between adjacent surfaces of the discs. The write sequence is repeated in each adjacent region until all regions are full. The resulting trapezoidal serpentine pattern of actuator movement and head switches is repeated until all of the write operations are complete.
    Type: Grant
    Filed: June 4, 2003
    Date of Patent: December 27, 2005
    Assignee: Seagate Technology LLC
    Inventors: Joseph L Wach, Khalil B Dizaji
  • Patent number: 6970311
    Abstract: A recording system of a magnetic tape drive is operated to cause one separate set of write heads to write data discontinuously to magnetic tape as received, and to save the data, and, during the same operation, to cause another separate set of write heads to rewrite data to magnetic tape in a continuous arrangement. The writing may be in parallel and simultaneous. Thus, during the same operation, and at the same time, the separate sets of the plurality of write heads, temporarily write the received data to magnetic tape so that the sender can erase its copy, and rewrite the saved data to the magnetic tape in a permanent arrangement, without waiting to complete first writing received data, to complete subsequently rewriting the data, and repeating.
    Type: Grant
    Filed: August 18, 2003
    Date of Patent: November 29, 2005
    Assignee: International Business Machines Corporation
    Inventor: Glen Alan Jaquette
  • Patent number: 6963462
    Abstract: For the purpose of providing technique by which even when large skew of a disk or a head occurs due to a thermal shock, an outside shock, or the like, a servo signal area is not extended, and a performance loss caused by head change is not produced, a servo detection control system according to the present invention comprises: a learning means by head change including a servo sector interval measuring unit for measuring an interval of servo signal areas, which may occur at the time of head change among a plurality of heads; a time difference calculating unit for calculating head-change time difference from a value measured by the servo sector interval measuring unit; and a time difference storage unit for storing a result of calculation made by the time difference calculating unit; and a compensation and control means for compensating start timing of servo detection after head change using a stored value of the time difference storage unit.
    Type: Grant
    Filed: February 20, 2002
    Date of Patent: November 8, 2005
    Assignee: Hitachi Global Storage Technologies Japan, Ltd.
    Inventor: Naoki Satoh
  • Patent number: 6952320
    Abstract: The present invention relates to repeatable runout (RRO) compensation of servo control systems that can be used in disc drives or spin-stands. The RRO relates to eccentricity between servo tracks, which were written onto a disc prior to the installation of the disc into the disc drive or spin-stand, and an axis of rotation of the disc. The present invention compensates the servo control loop by canceling the RRO and controlling a head to follow virtual tracks which are eccentric to the data tracks defined by the servo tracks and concentric with the axis of rotation of the disc.
    Type: Grant
    Filed: December 8, 2000
    Date of Patent: October 4, 2005
    Assignee: Seagate Technology LLC
    Inventors: Brian Pollock, Alexei H. Sacks, Brian Sudman, James H. McGlennen, Reed D. Hanson
  • Patent number: 6950258
    Abstract: In a head positioning method and device in which the position of servo signals between heads is not uniform, it is aimed to reduce the time taken to find the servo signals when heads are switched. A storage disk device comprises storage disks with the servo signals, a plurality of heads that read the information from the storage disks, an actuator that moves the heads, and a control circuit that positions the heads based on the servo signals read from the storage disks by a selected head. This control circuit includes a synchronization circuit that, in response to a head switching cue, synchronizes the time of a servo gate signal (of the head to which switching is directed) for detecting a servo signal with the time of the servo signal read by the head to which switching is directed, and a processing circuit that reads the servo signal for the head in response to the synchronized detection signal and positions the head in response to the servo signal read.
    Type: Grant
    Filed: March 8, 2001
    Date of Patent: September 27, 2005
    Assignee: Fujitsu Limited
    Inventor: Kazuhiko Takaishi
  • Patent number: 6934105
    Abstract: The present invention decreases the number of repositions during read back by making use of multiple read elements associated with each data track. A tape system includes a tape head with two read elements associated with each data track to be simultaneously read. Each read element generates a read signal in response to information recorded on the data track. Read electronics convert the read signal into read data. Control logic selects one of the two read elements as a source for output data for each data track. In response to a read error, output data is obtained from the other of the two read elements.
    Type: Grant
    Filed: October 15, 2002
    Date of Patent: August 23, 2005
    Assignee: Storage Technology Corporation
    Inventor: James C. Cates
  • Patent number: 6917485
    Abstract: An apparatus and method for dynamic head switch timing recalibration are provided. With the apparatus and method, a determination is made as to whether a difference in a reference head switch timing and the head switch timing at a later time is sufficient to meet a certain criteria. If the difference meets the criteria, a recalibration of the head switch timing is performed. For example, in a preferred embodiment, the criteria is a number of address mark (AM) misses during a head switch operation. If this predetermined number of AM misses is detected, then it is determined that a recalibration is necessary since the predetermined number of AM misses is an indication that the head switch timing has changed significantly from the reference head switch timing.
    Type: Grant
    Filed: June 20, 2003
    Date of Patent: July 12, 2005
    Assignee: Seagate Technology LLC
    Inventors: David Louis Schell, Chris Thomas Settje, Steven Alan Koldewyn, Kar Wei Koay, Abhay T. Kataria, Marinko Bosnich, Mike E. Baum
  • Patent number: 6903892
    Abstract: The present invention decreases the number of repositions during read back by making use of multiple read elements associated with each data track. Each of a plurality of sets of read electronics receives the read signal from either one or the other of the two read elements associated with each data track and converts the received read signal into read data. For each data track, control logic selects one of the two read elements as a source for output data. In response to a determination that a read error has occurred, the control logic selects the other of the two read elements as the source for output data. For each data track, one read element is offset relative to the other read element in an offset direction normal to the tape direction.
    Type: Grant
    Filed: October 25, 2002
    Date of Patent: June 7, 2005
    Assignee: Storage Technology Corporation
    Inventor: James C. Cates
  • Patent number: 6879454
    Abstract: A modified disk drive that includes means for selectively and permanently disabling the write mode of the hard disk drive by the use of programmable read only memory (PROM) circuitry is provided. One method of use employs selectively blowing a PROM fuse in the arm electronics of the hard disk drive to prevent further writing to a respective disk surface in the hard disk drive. A second method of use employs selectively blowing a PROM fuse in processor-accessible memory, to prevent further writing to a section of logical block addresses (LBAs) corresponding to a respective set of data sectors in the hard disk drive.
    Type: Grant
    Filed: July 11, 2003
    Date of Patent: April 12, 2005
    Assignee: International Business Machines Corporation
    Inventors: Daniel James Winarski, Kamal Emile Dimitri
  • Patent number: 6865051
    Abstract: A disk device has eccentric misalignment between a plurality of disk surfaces. In order to prevent transient phenomena due to differences in the eccentric trajectories during head switching, a head position control method performs feed forward control for a plurality of disk surfaces by application of the eccentricity correction current of respective heads, and when switching heads, predicts the velocity fluctuation or current step differential between heads from the eccentricity correction current, and thus corrects the control system to eliminate velocity fluctuation and current step differential.
    Type: Grant
    Filed: February 25, 2003
    Date of Patent: March 8, 2005
    Assignee: Fujitsu Limited
    Inventor: Kazuhiko Takaishi
  • Patent number: 6844995
    Abstract: A head protection device in a data recording circuit is disclosed in which write-current of a given level that corresponds to a high or low level of coercive force of the magnetic recording portion of a recording medium is provided as an output and supplied to a magnetic head for data recording and reproduction. The data recording circuit comprises an alternate write-current supply portion for alternately providing, by a suitable current switching means, a low write-current corresponding to a low coercivity magnetic head and a high write-current corresponding to a high coercivity magnetic head, a common output portion for providing data to be recorded using a low current or a high current from the alternate write-current supply portion. The low coercivity magnetic head and the high coercivity magnetic head can be at least electrically switched. A current protection portion for a current switching means is provided so as to prevent generation of high write-current at the alternate write-current supply portion.
    Type: Grant
    Filed: June 26, 2002
    Date of Patent: January 18, 2005
    Assignee: Sankyo Seiki Mfg. Co., Ltd.
    Inventor: Hisashi Yamamoto
  • Publication number: 20040246614
    Abstract: A disc drive has transducers supported by an actuator to fly proximate data tracks on surfaces of rotating information storage discs. Each of the discs is partitioned into concentric regions. A control system arranges the deposition of data in write operations to the tracks on the disc surfaces, as data is written to the discs, such that the data is sequentially organized both on the tracks and within each of the regions. The control system writes data from a track adjacent a first region boundary in a first direction to a second region boundary until all tracks in a region are full. The control system executes a head switch between adjacent surfaces of the discs. The write sequence is repeated in each adjacent region until all regions are full. The resulting trapezoidal serpentine pattern of actuator movement and head switches is repeated until all of the write operations are complete.
    Type: Application
    Filed: June 4, 2003
    Publication date: December 9, 2004
    Inventors: Joseph L. Wach, Khalil B. Dizaji